bullock



11.1015011910 2'Sheets-Sheet1.

M. C. BULLOCK 82; S. W.. DOUGLASS.' l

MOLD. No. 501,915. Patented July 25 1893.

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H 2 Sheets-Sheet 2. lVI. 0. BULLOCK 8a S. W. DOUGLASS.

MOLD.

Patented July 25, 1893.

(No MfG-(1R11.)

IIIIIIIIIII Illllllllll! i UNITED STATES PATENT OFFICE.

MILAN C. BULLOCK AND SAMUEL W. DOUGLASS, OF CHICAGO, ILLINOIS; SAID DOUGLASS ASSIGNOR TO SAID BULLOCK.

MOLD.

SPECIFICATION forming part of Letters Patent No. 501,915, dated July 25, 1893. Application tiled November 26, 1889. Serial No. 331,596. (No model.)

To a/ZZ whom it may concern:

Be it known that we, MILAN C. BULLOCK and SAMUEL W. DOUGLASS, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Molds; and we do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of referlo ence marked thereon, which form a part of this specification.

This invention relates to molds for casting metal tubular cutter heads for rock core-drills, said heads having cutting diamonds or points :5 located in their annular working faces and held in place by the metal of the head as poured in a molten state about them.

The principal object of the invention is to provide a construction by which a cutter zo head of this class may be cast in a finished or completed state ready for use without subsequent finishing or manipulation, and in addition to this principal end the invention has the secondary object of providing a mold 2 5 which is capable ot' being detached from the casting promptlyr after the metal forming the same has been poured and set in order that said casting may not break in cooling within the mold, and also that it may be placed in 3o sand as soon as the metal shall have set sufficiently to retainits form, so that in further coolingv it may not be excessively chilled.

In the accompanying drawings which illustrate our invention in what we believe to be its best form: Figure l is a View in side elevation, of a mold constructed in accordance with our invention. Fig. 2 is atop plan view of the same. Fig. 3 is a vertical, sectional view on the line 3 3 of Fig. 2. Fig. 4 is a 4o vertical, sectional view taken on the line 4 4 of Fig. 2. Fig. 5 is a top plan view of a wedge which is inserted within the core of the mold. Fig. 6 is a view in side elevation of said wedge. Fig. 7 is a central, vertical section, of a contracting core which forms a part of the mold with the wedge piece thereof removed. Fig. 3 is a horizontal, sectional view of the said core on the plane indicated by the line 8 8 of Fig. 7, showing the wedge piece there- 5o of in place. Fig. 9'is a horizontal, sectional viewof the mold taken on the line 9 9 of Fig. l. Fig. 10 is an enlarged vertical, sectional view of the upper part of the mold, illustrating a modified form of construction embodying our invention, the plane of the section being the same as that indicated by the line 3 3 of Fig. 2. Fig. ll is a face l View of a cutter head such as is cast in the form of mold shown in the foregoing figures. Fig. 12 is an axial section of a cutter head, 6c f such as is cast by the mold shown in Figs. l

to 9 inclusive. Fig. 13 is an axial section of the cutter head, such as is cast by the mold shown in Fig. 10.

Referring to Figs. l to 9 inclusive of the 65 drawings, A designates a circular base of the mold, the base being provided y at each side with an upright A which is integral with the base.

A2 designates a cylindrical head which is 7c formed integrally with the uprights A and extending across the space between the said uprights. The base, the uprights and the head together, form the lower part of the mold and are made in two vertical sections, the parting line of which is vertical and is indicated at a, said parting line passing through each of the uprights A and dividing them about equally, as shown in Figs. l and 3.

The said sections of the lower part ot' the 8o mold, lettered respectively d'0? are provided with dowels alg (see Fig. 9) to insure thepreoise registry of the sections when the latter are placed together. p To secure said sections of the mold together, hinged horizontal clamp bolts a3 a3 are employed, said bolts being hinged between suitable lugs a4 a4 uponI the lower part of the front section a2 and provided on their free screw-threaded ends with nuts a5 a5. Lugs a6 a6 are formed upon the 9o rear section a of themold and adjacent to the parting line thereof, between which lthe clamp bolts may swing and'against which the nuts on said clamp bolts bear, to hold the sections of the mold rigidly together.

A3, Figs. 3, 4 'and 9, designatesa hinged table or support located between the uprights A of the mold frame and, hinged to the upl per part of the rear section a at a point just below the cylindrical head A2 and near the xo' rear-of said head, as shown at a7. Said hinged table AS is provided at about its center with a circular opening A4 which is located centrally under the cylindrical head A2, when the said table A3 is in a horizontal or operative position. The front end of said table is bifurcated, as shown, to form an open slot 0.8, which is located just below the front edge of the cylindrical head A2.

A5designates a hinged operatively vertical screwthreaded bolt pivoted to the lower side of the head A2between the frarne uprights A and provided on its lower end with a nut ai. This hinged bolt is adapted to swing into the slot as, so that the nut a thereon may engage the under part of the bifurcation as, and sustain the table in its horizontal position. When the bolt is swung out of the slot as, the table may be lowered upon its hinge-bolt a2. A

The head A2 is provided centrally with a circular vertical opening d10, having a diameter equal to the interior diameter of the cutter head which is to be cast in the mold and is formed with a plurality of vertical or spiral grooves a17 which serve to prevent the wedge of the mold from turning therein, as hereinafter explained. lAbout midway vertically of the head, the openingen10 is enlarged, as seen at 0.11, to a diameter equal to the exterior diameter of the cutter head to be cast,'

'said enlargement having its side walls Vertical and its annular bottom wall horizontal. Said lower wall of the opening a is provided at intervals with uprising ribs or projections Q12 (i12, (seen in Fig. 9 and in dotted lines in Figs. 3 and 4,) which serve to form the-waterways or passages for water across the annular face of the cutter head. The sides or vertical walls of the said opening a are provided with vertical ribs a als, (Figs. 3, 4 and 9) which serve to form the waterways in the side of the cutter head. The mold has a separate upper part B, having a central opening b2 and made in two vertically divided sections B B2, provided with dowel pins b9 b2 on one member, which enter corresponding holes b10 in the other. The upper end of the opening 127 is flared outwardly as at b, tofacilitate the pouring of the metal into the mold.

The top of the head A2 is provided with annular inclined and horizon-tal'surfaces, respectively lettered a and a, Figs. 3 and 4t, which form a seat for the top part B of the mold.

The section B2 is provided near its parting face b with hinged screw-threaded horizontal bolts b h', having heads or nuts b2 b2 and adapted to swing across the parting line into engagement with lugs b3 b2 on the other section B', to rigidly hold the sections together. The lower face of the upper part B of the moldV has the downwardly and inwardly inclined faces b4 and h5, which conform to the upper inclined and horizontal faces 0f the head A2. An annular, vertical shoulder b( between the said inclined and horizontal faces b4 and h5 lits within the annular, vertical wall al of the cylindrical head A2 and retains the parts in concentric position. The opening b2 has at its lower end, an enlarged portion bs, which is of a diameter equal to the opening a in the head A2, (measuring between the surfaces of the ribs am) and forms an upward continuation of the said opening all. The chamber formed by the openings @12W and 58, is the matrix in which the cutter head is cast. The part of the cutter head which is formed within the part h2' of the matrix is the part which is afterward provided with screwthreads for its attachment to the lower end of the drill tube.

The core of the mold, indicated as a whole by the letter C, comprises, as here shown, a wedge C and a sleeve or contracting core D, surrounding said wedge. This wedge C has an enlarged base C2 and an upright reduced ,part C2, which latter is of the same diameter as the lower part of the openinga10 in the head A2. The upright C3 of the wedge is provided jvith a plurality of vertical or spiral ribs c c which interfit with the grooves al? of the opening 0,10 inv the head A2, and thus prevent the wedge from being turned within the head. The base of the wedge is larger than said opening am and rests upon the hinged table A3, the wedge being passed upwardly through the said opening 01,10 and the table being then swung up under it and secured in its horizon-` tal position. When the wedge C is in this position in the mold, the part C3 thereof extends upwardly, desirably to a point about even with the upper end of the enlargement et of the opening in the head. The sides of the body of said upright part are or may be vertical, while the ribs c c thereon may also be vertical or they may taper inwardly and upwardly from a point about even with the bottom of the opening an. When the said wedge is in place, the ribs or projections c thereon are opposite the spaces between the ribs 0.13, as best shown in Fig. 9, and, as also shown in Fig. 9, the projections or ribs cd2 in the bottom of the cavity a are not radially arranged but lead obliquely from one of the ribs a to an adjacent rib c on the wedge.

For convenience of con struction, an annular groove cis formed in thelowerend of the uprising part C3 of the wedge adjacent to the base C2, as shown in Fig. 6, said wedge being preferably cast or forged of cylindric form and the ribs c formed thereon by planing out the metal between them. Above its u pri ght part C3, the wedge is again reduced in size at c2 and presents a shoulder c3. From the top of the reduced portion c2, the wedge is still further reduced in size and presents an upwardly eX- tending and 'tapering stem C4. An upwardly facing shoulder ctie thus formed between the reduced portion c2 and the stem C4, and said shoulder C4t isy provided withV an annular groove ordepression c5 surrounding the base of the stem for a purpose to be presently explained. The contracting coreD is hollow and its interior is providedr with a tapering portion CZ the walls of which converge up-` Wardly, and which fits around thestem C4 of lOO IIO

the wedge, a flange d at the bottom of said tapering portion d to fit into the annular groove c5, and a vertical part d2 closely embraces the reduced portion c2 of the wedge. The bottom of said contracting core D rests upon the shoulder c3 of said wedge.

In Figs. 7 and 8, the core D is shown in detail. To adapt said core to be contracted, it is slitted at one side throughout its length, as shown clearly at d3 in Fig. 8. The slit cl3 is wider at the inner than at the exterior surbeing secured to the core by across-pin d6,

and the object of this ring d5 being to prevent undue expansion of the core. The wedge-shaped piece CF, conforms to the contour of the tapered slot d3 and has the shape ofthe core in its outer and inner faces, and when in place presents smooth surfaces continuous with the surfaces of the core.

From the abovedescription, it is manifest that when the wedge piece Z7 is in place in the core and the core is passed down over the stem 0.4, the said stem A prevents the wedge-piece from falling out, and the flange d entering the annular groove c5 of the wedge C serves to prevent the expansion of the lower part of said core, while its upper part is held from expansion by the ring d5.

The annular space inclosed by the several parts of the mold described, gives a casting which hasv the appearance in end View indicated by Fig.,ll and in axial section by Fig. 12, e being the external grooves or waterways, formed by the ribs als, e2, the interior grooves or waterways formed by the ribs c and e grooves or depressions extending across the end face of the casting and formed by the projections 0.12, and giving communication between said outer and inner waterways, all of said grooves or depressions being thus formed by the several sets of ribs and projections of the mold, wedge and core, as above set forth.

T he diamonds are placed in the mold before the metal is poured therein and are embedded in said metal, some of them e3 being located at the outer and others e4 at the inner margin lof the cutter face between the depression e', as shown in Figs. ll and l2. To hold the diamonds in the bottom of the mold and against its outer and inner walls, small metal pins are projected through correspondingly small passages in the metal walls of the mold and are Vmade to bear at their ends againstthe stones. The holding pins for the inner series of stones are shown at @18, Fig. 4, as passing,

inwardand downward through'the YmoldA6 being thumb screws threaded into the body of the mold to push the pins Asinwardly endwise. The holding pins for keeping the outer series in place are shown at c6, Fig. 3, as passing inward and downward through holes in the wedge C. These pins are so inclined, as shown, as to hold the `stones to the bottom as well as to the sides of the mold and the' pins c6 are accessible for manipulation through the cavity C5 in the bottom of the wedge C.

The parts described as entering into the mold are put together and operated as follows: First, the two sections a a2 of the lower portions of the mold are placed together and secured by the hinged clamp bolts a3.- `The wedge C is then passed up through the grooved opening d10 in the head A2, with its ribs fitting the grooves of said opening, and the horizontal table or support A3 is then lifted to a horizontal position and secured by the bolt A5. The outer set of diamonds or cutting points are then'inserted i'n their proper positions and the wires or pins c6 (which had been previously placed in the wedge but in ai retracted position) are forced outwardlyk by pressure on their upper or outer ends or by means of pliers seizing them in the cavity of said wedge, until they bear against said stones or points. The upper ends of said wires or pins c6 desirably project a little beyond the outer surface of the wedge so as to be engaged and held in place by the contracting core D which is next applied to the wedge in the position shown in Figs. 3 and '4. The inner set of diamonds or cutting points are next placed in position and the thumb screws A6 turned to force the pins als against them. The two sections B B2 of the upper part of the mold are then secured together and placed upon the head A2. The mold is now complete. Be-

fore pouring the metal into the mold the latter is heated to a proper temperature in a furnace, after which it is placed in an upright position to receive the melted metal. After the metal is poured, and hasvset the hinged support A3 is released and allowed to drop, leaving the wedge C unsupported. A blow struck upon the upper end of the stem C4 of this wedge;

drives the latter downl'through the contracting core and head A2,c'utting off the pins or wires c6 and permitting the wedge to be removed through the space between the uprights A. There being now nothing to interiorly supportk the wedge shaped fillingipiece C17. in the slot of the contracting core D, it may be forced inward by contraction of the core as the latter is compressed bythe shrinking of,

when this is done the outer partsof the mold are successively parted and the casting released. The casting which will now have been sfuficiently setto retain its form will then be taken out and put in sand to cool off slowly and thus avoid excessive chilling of `the same. The holding pins or wires a which pass ICO EIO

through the body A2 of the mold being small are broken off when the outer portion of the mold is parted.

The mold above described has several -advantages, relating to the facility and the certainty of position with which the diamonds may be placed and retained therein, to accuracy in the form of the casting and to the durability of the cutter head cast in said mold.

The rst of these advantages constitutes a distinction between the cutter head cast complete, as described, and any other tool provided with cutting diamonds or points heretofore made and with which we are acquainted.

So far as We are informed, an integral tubular bit or cutter head has never before been cast complete with the diamonds in it and held in place by the metal as originally poured around them. The former practice has generally been to cast separate pieces or sections with one ora few of the diamonds in them which are to enter into the finished tool, and to set such separate pieces into the metal of the tool, as, for example, in a saw blade. In the present case, the cutter head is integral or formed of a single piece of metal containing all the diamonds or cutting points which it is to carry, supported by the metal as cast about them. The possibility of making the tool thus com plete in the first instance is dueto the use of the mold or to the mold and the holding wires by which the diamonds are held in place during the process of casting, the walls of the mold and its xed bottom insuring the positions of the diamonds in a single plane and in concentric circles. Such accuracy in the position of the diamonds is practically of great importance, inasmuch as, if one of several stones excessively projects beyond the proper plane of the cutting face, an excess of work is thrown upon said stone and its cutting edges are soon dulled. The irregularity of its position out of its plane and also the position of a stone outside of its proper circle gives a vibratory motion to the tool in operation which interferes with the accuracy of its work and also with the durability of the tool. When the diamonds are set in separate pieces and affixed to a tool,whether it be a saw blade or a cutter head, this absolute accuracy cannot be attained.

The accuracy in the form of the casting produced by the mold is in itself of material advantage inasmuch as thereby all subsequent nishing of the castingis rendered unnecessary excepting the cutting of a screw thread or the provision of other means thereupon of attaching the head to a drill rod. But such accuracy has direct reference to the durability of the cutter head in use, inasmuch as all filing away of portions of its surface to produce accuracyis obviated. The su perficial chill produced by the mold is the same in all portions of its surface, so that it wears with uniformity at all points exposed to the same friction or strain.

Thevuse of a contracting core D provides for the proper shrinking of the casting in its rst cooling or setting without fracture of said casting and without the destruction of .the core, which may be repeatedly used an indefinite number of times.

In Fig. l0 a modied form of the mold is illustrated having reference to the production or a cutter head the interior opening of which shall contract downwardly to form a chamber for a core-lifting ring and which shall bc adapted more especially to receive a thread upon its inner upper surface for the introduction of an externally threaded section of drill tube. This modification presents no departure from the invention already described as being illustrated in Figs. l to 9 inclusive.

Fig. 13 illustrates as a vertical, axial section, the form of cutter head which will be produced by a mold constructed in detail as shown in Fig. 10, the lower or Working face of the cutterhead beingin this case the same as produced in the mold as shown in preceding figures and as particularly illustrated in Fig. 1l.

In Fig. l0 we have illustrated the head A2, as provided with an annular bushing d20 forming a removable part of the mold. This construction will be a convenience in manufacture and may be applied to the mold as otherwise illustrated in preceding figures.

Itis manifest that the mold above described as being particularly adapted for casting cutter heads for rock drills may be employed for casting other similarly shaped or hollow metal articles and we are therefore not restricted to the use of the mold herein described and claimed for casting such cutter heads alone. We also do not wish to restrict ourselves to the details of construction herein shown, inasmuch as various modifications may be made without departure from our invention, the

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primary essential of which is that the mold comprises an inner Wall or core which is collapsible, and to this end is made in sections.

We claim as our inventionl. A metal mold, comprising a central member having transverse holes therein to receive holding wires or pins by which to retain diamonds or other separate parts, in proper position Within the mold during the pouring; the said central member being provided with a cavity affording access to the holding wires or pins while said member is in position in the mold,'substantially as set forth.

2. A sectional metallic mold comprising an external vertically divided bod y portion forming the external walls of the mold and having an opening through its bottom, a tapered wedge-shaped member projecting upward through said mold, and wholly separate from the mold, a contractible tubular core or sleeve surrounding the tapered member and located wholly separate therefrom within the mold and slit longitudinally at one side and also recessed longitudinally at another side, and

a wholly separate spreader -piece wedgeshaped in cross-section and inserted into the split of the core, substantially as set forth.

3. kA sectional metallic mold, comprising an external vertically divided body portion having its two sections hinged together and forming the external walls of the mold and having an openingin its bottom, a tapered member wholly separate from the body portion of the mold and removable downwardly from the mold through the bottom oppening thereof, a movable support for the tapered member hinged beneath the body of the mold and having also a central opening, a contractible tubular core or sleeve surrounding the tapered member and located wholly separate therefrom within the mold and split longitudinally at one side and also recessed longitudinally outward at another side, and a wholly separate spreader-piece wedge-shaped in cross-section and inserted into the split of the core, substantially as set forth.

4. A sectional metallic mold, comprising a vertically divided external casing forming the body portion of the mold and having an opening in its bottom, the two portions of the casing being hinged together and having connecting attachments opposite their hinge, a wedge-shaped member wholly separate from the mold and projecting upwardly through the same and also removable downwardly through the bottom of said mold, a contractible tubular core'or sleeve surrounding the tapered member and located wholly separate therefrom within the mold and split longitudinally at one side and also recessed outward longitudinally at another side, a separate wedge-piece arranged to enter the longitudinal split of the sleeve a retaining-band embracing one end of the core or sleeve, and

land a body portion integral withthe support,

said base, support and body-portion being vertically divided and hinged together, and the internal cavity ofthe body-portion being of greater diameter at its upper than at its lower portion, a vertically divided top piece for the rnold wholly separate therefrom and having an inlet opening communicating with the cavity of the mold, ribs and projections located within the cavity of the mold and serving to form the water-ways of the molded article, a support hinged below the body-portion of the mold and having a central opening, a tapered member wholly separate from the mold and resting upon the support, a longitudinally split and recessed coutractible tubular core having external ribs to form the internal water-Ways of the molded article, and located within the mold and surrounding the tapered portion, and also wholly separate from the mold and the tapered portion, and a spreader wedge-shaped transversely, insert.-l ed into the split of the core, substantially as set forth.

In testimony that we claim the lforegoing as our invention we affix our signatures in presence of two witnesses.

MILAN C. BULLOCK. SAMUEL DOUGLASS. Witnesses:

HARRY COBB KENNEDY, P. H. T. MASON. 

